
/* ----------------------------------------------------------------------
 * Project:      CMSIS DSP Library
 * Title:        arm_minkowski_distance_f32.c
 * Description:  Minkowski distance between two vectors
 *
 *
 * Target Processor: Cortex-M cores
 * -------------------------------------------------------------------- */
/*
 * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved.
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the License); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "arm_math.h"
#include <limits.h>
#include <math.h>


/**
  @addtogroup FloatDist
  @{
 */


/**
 * @brief        Minkowski distance between two vectors
 *
 * @param[in]    pA         First vector
 * @param[in]    pB         Second vector
 * @param[in]    order      Distance order
 * @param[in]    blockSize  Number of samples
 * @return distance
 *
 */

#if defined(ARM_MATH_MVEF) && !defined(ARM_MATH_AUTOVECTORIZE)

#include "arm_helium_utils.h"
#include "arm_vec_math.h"

float32_t arm_minkowski_distance_f32(const float32_t *pA, const float32_t *pB, int32_t order, uint32_t blockSize)
{
	uint32_t        blkCnt;
	f32x4_t         a, b, tmpV, sumV;

	sumV = vdupq_n_f32(0.0f);

	blkCnt = blockSize >> 2;
	while (blkCnt > 0U) {
		a = vld1q(pA);
		b = vld1q(pB);

		tmpV = vabdq(a, b);
		tmpV = vpowq_f32(tmpV, vdupq_n_f32(order));
		sumV = vaddq(sumV, tmpV);

		pA += 4;
		pB += 4;
		blkCnt--;
	}

	/*
	 * tail
	 * (will be merged thru tail predication)
	 */
	blkCnt = blockSize & 3;
	if (blkCnt > 0U) {
		mve_pred16_t    p0 = vctp32q(blkCnt);

		a = vldrwq_z_f32(pA, p0);
		b = vldrwq_z_f32(pB, p0);

		tmpV = vabdq(a, b);
		tmpV = vpowq_f32(tmpV, vdupq_n_f32(order));
		sumV = vaddq_m(sumV, sumV, tmpV, p0);
	}

	return (powf(vecAddAcrossF32Mve(sumV), (1.0f / (float32_t) order)));
}

#else
#if defined(ARM_MATH_NEON)

#include "NEMath.h"

float32_t arm_minkowski_distance_f32(const float32_t *pA, const float32_t *pB, int32_t order, uint32_t blockSize)
{
	float32_t sum;
	uint32_t blkCnt;
	float32x4_t sumV, aV, bV, tmpV, n;
	float32x2_t sumV2;

	sum = 0.0f;
	sumV = vdupq_n_f32(0.0f);
	n = vdupq_n_f32(order);

	blkCnt = blockSize >> 2;
	while (blkCnt > 0) {
		aV = vld1q_f32(pA);
		bV = vld1q_f32(pB);
		pA += 4;
		pB += 4;

		tmpV = vabdq_f32(aV, bV);
		tmpV = vpowq_f32(tmpV, n);
		sumV = vaddq_f32(sumV, tmpV);


		blkCnt --;
	}

	sumV2 = vpadd_f32(vget_low_f32(sumV), vget_high_f32(sumV));
	sum = vget_lane_f32(sumV2, 0) + vget_lane_f32(sumV2, 1);

	blkCnt = blockSize & 3;
	while (blkCnt > 0) {
		sum += powf(fabsf(*pA++ - *pB++), order);

		blkCnt --;
	}


	return (powf(sum, (1.0f / order)));

}

#else


float32_t arm_minkowski_distance_f32(const float32_t *pA, const float32_t *pB, int32_t order, uint32_t blockSize)
{
	float32_t sum;
	uint32_t i;

	sum = 0.0f;
	for (i = 0; i < blockSize; i++) {
		sum += powf(fabsf(pA[i] - pB[i]), order);
	}


	return (powf(sum, (1.0f / order)));

}
#endif
#endif /* defined(ARM_MATH_MVEF) && !defined(ARM_MATH_AUTOVECTORIZE) */


/**
 * @} end of FloatDist group
 */
